The present invention relates to hydraulic pressure control apparatus and method for a continuously variable transmission (belt type continuously variable transmission) of an automotive vehicle. The present invention particularly relates to hydraulic pressure control apparatus and method for the continuously variable transmission of the vehicle which appropriately control a hydraulic pressure of a working oil to operate the continuously variable transmission when a shift range of the transmission is switched from a neutral range (N range) to a running range (D range).
A Japanese Patent Application First Publication No. 2004-124959 published on Apr. 22, 2004 exemplifies a previously proposed hydraulic pressure control apparatus for a continuously variable transmission (belt-type continuously variable transmission). In the previously proposed hydraulic pressure control apparatus, in order to suppress an overshoot developed in a line pressure PL, when a time duration for which actual line pressure PL is equal to or higher than a preset value is continued for a predetermined time, particularly, during an engine cold start time at a low temperature, a controller, determining that line pressure PL is in a pressure adjusting state, thereafter, sets the command pressure to a maximum value.